This invention relates to a disk control system for controlling a plurality of disk devices and relates in particular to a method for improving the high speed operation of the disk control system, achieving a lower cost and improving the cost performance.
A diskarray system for controlling a plurality of disk devices is utilized as a storage system in computers. A diskarray system is for instance disclosed in “A Case for Redundant Arrays of Inexpensive Disks (RAID)”; In Proc. ACM SIGMOD, June 1988 (Issued by Cal. State Univ. Berkeley). This diskarray operates a plurality of disk systems in parallel and is a technique that achieves high speed operation compared to storage systems utilizing disks as single devices.
A method using the fabric of a fiber channel is a technique for mutually connecting a plurality of hosts with a plurality of diskarray systems. A computer system using this technique is disclosed for instance in “Serial SCSI Finally Arrives on the Market” of Nikkei Electronics, P. 79, Jul. 3, 1995 (No. 639) as shown in FIG. 3. In the computer system disclosed here, a plurality of host computers (hereafter simply called hosts) and a plurality of diskarray systems are respectively connected to a fabric device by way of fiber channels. The fabric device is a switch for the fiber channels and performs transfer path connections between the desired devices. The fabric device is transparent to (or passes) “frame” transfers which are packets on the fiber channel. The host and diskarray system communicate between two points without recognizing the fabric device.